Young, free and simple

16 September 2006

A neuroscientist would tell you that the poor decisions and risky behaviour of adolescents are not just the result of raging hormones or a double shot of attitude. Instead, they are at least partially a result of differences in brain anatomy between teens and adults. …

Earlier this month, the neuroscientist Dr Sarah-Jayne Blakemore [UCL Institute of Cognitive Neuroscience] described another role that the prefrontal cortex plays in annoying teenage behaviour. Speaking at the BA Festival of Science in Norwich, Blakemore focused on the medial prefrontal cortex, which is associated with higher-level thinking, empathy, guilt and understanding people’s emotions. She said that scientists have found that when teenagers make decisions, they under-use their medial prefrontal cortex. Now why is this not surprising? Instead, an area toward the back of the brain, involved in perceiving and imagining actions, takes over.

This, she said, “implies that they are less likely to think about how they themselves and how other people will feel as a result of their intended action”.

A teenager’s judgment of what they would do in a given situation is driven by the simple question: “What would I do?”, she explained. Adults, by contrast, ask: “What would I do, given how I would feel and given how the people around me would feel as a result of my actions?” …

As Blakemore said in Norwich, it’s clear that teenagers are dealing not only with massive hormonal shifts, but also significant neural changes. “They come on in great spurts and puberty is one of the most dramatic developmental stages.” …